Apparatus and method for drying tubing

ABSTRACT

A drying apparatus for use in the continuous process of forming tubing or treating wire in which one of the steps in the operation is either cooling or washing by means of a fluid. A suction system has a through passageway in a drying or cooling head which contemplates the feeding of the formed tubing or treated wire through a T-shaped head connected to a source of vacuum. The fluid is drawn from the surface of the passing tubing or wire by the inrush of air into the head, which suction line transports the removed fluid to a vacuum chamber receiving device. The collected fluid from the vacuum chamber may be returned to the cooling or treating tank or may be discharged to a waste disposal.

United States Patent [72] Inventor Raymond A. Heisler 657 Dakota Trail, Franklin Lakes, NJ. 07417 [21] Appl. No. 856,313 [22} Filed Sept. 9, 1969 [45] Patented Apr. 13, 1971 [54] APPARATUS AND METHOD FOR DRYING TUBING 12 Claims, 2 Drawing Figs.

[52] US. Cl 34/9, 34/16, 34/155 [51] Int. Cl F26b 3/00 [50] Field ofSearch 34/9, l2, 15, 16, 155

[56] References Cited UNITED STATES PATENTS 2,597,801 5/1952 Jellinek 34/155X 3,097,078 7/1963 Turner 34/155 Primary Examiner-John J. Camby AttorneyRalph R. Roberts ABSTRACT: A drying apparatus for use in the continuous process of forming tubing or treating wire in which one of the steps in the operation is either cooling or washing by means of a fluid. A suction system has a through passageway in a drying or cooling head which contemplates the feeding of the formed tubing or treated wire through a T-shaped head connected to a source of vacuum. The fluid is drawn from the surface of the assing tubing or wire by the inrush of air into the head, which suction line transports the removed fluid to a vacuum chamber receiving device. The collected fluid from the vacuum chamber may be returned to the cooling or treating tank or may be discharged to a waste disposal.

Patented .April 13, 1971 INVEN'IOR. RAYMOND A. HE/SL ER AGENT APPARATUS AND METHOD FOR DRYING TUBING BACKGROUND OF THE INVENTION 1. Field of the Invention The field of art to which this invention pertains is found in the processing of plastic or nonmetallic articles wherein the outer surface is treated as by drying through the use of vacuum. Another field is in the art of molding in which the plastic tubing is extruded and is cooled in a tank of water and the like and after cooling requires the subsequent removal of the water from the surface of the tubing in an even and equal manner.

2. Description of the Prior Art In the extruding of tubing or rods from material such as plastic, rubber and the like, the material as it is extruded is, of course, quite hot and must be cooled before it can be stored on reels and the like. This storage often requires that the rod or tubing be brought to room temperature before the rod or tube be stored on a reel prior toshipment to the eventual consumer. The usual means of cooling is by transporting the rod or tubing through long tanks of cooled water but in order to render the surface of the cooled rod or tubing absolutely dry for safe storage, it is necessary that a drying operation be employed as or after the last stage of cooling in the fluid tank. The rod or tubing as it is drawn from the cooling bath, usually water, is usually'brought in way of a drying apparatus for removing the fluid from all of the surface of the rod or tubing before it is wound on a reel or other storage devices. Whether the plastic, rubber or the like being extruded is a tube or a rod of solid form of generally constant cross section, it is necessary that the drying of the extrusion be substantially equal on all surfaces in order to maintain surface quality and crosssectional size control.

It has been customary to pass the extruded product from the last cooling bath over a wiper and then to bring the extruded product in way of a series of airblast jets directed to impinge and blow the fluid from the surface of the extruded product. The use of an air jet, in addition to blowing the fluid from the extrusion, causes the fluid to be generally blown over a large area. Oftentimes the fluid, instead of all being blown from the advancing strand, has a tendency, because of surface adhesion, to leave a small amount which clings in droplets on the surface of certain portions of the extruded product. This product, instead of having an absolutely and equally dried outer surface, thus often is damp or wet in spots as it is wound on a reel which usually results in very unsatisfactory storing conditions of the extrusion if it remains wound on the reel for a length of time. The improperly dried extrusion when unreeled by the customer often sticks to itself. Because of this drying irregularity and also because of the scattering of the fluid being blown from the extrusion, it was found desirable and necessary to provide a more efficient and satisfactory water or fluid-removing apparatus. THis improved apparatus utilizes a vacuum source to insure that all of the lluid remaining on the surface of the extrusion not removed by a wiper as the extrusion leaves the cooling tank is removed by a drying T-head. The extrusion, after passing the wiper, is fed to and through a transverse passageway of determined cross section. This passageway, intermediate its ends, is connected to a vacuum source to provide a suction flow over the walls of the extruded product as it passes through the T-head. 'lhis suction flow removes the fluid from the surface of the traveling extrusion and the fluid after removal is lifted to a chamber device where it is accumulated and, if desired, the fluid may be returned to the cooling tank.

SUMMARY OF THE INVENTION After the product which is being cooled or treated by immersion is passed from the treating fluid tank and over and or through a wiper blade arrangement, the product is passed into and through a tubularshaped passageway ol' determined cross section. The midportion of this passageway is connected to a vacuum source whereby the product to be dried as it passed through this tube is wiped by theflow or air to the suction source. The fluid removed from the surface of the product is caused to be drawn through a connecting conduit to a wet-type vacuum tank where the collected fluid is caused to be either returned to the fluid-treating tank or is discharged to other accumulating and dispensing means. The exhaust of air from the vacuum tank is expelled from the tank in a conventional manner.

Although the following disclosure offered for public dissemination is detailed to insure adequacy and aid in understanding of the invention, this is not intended to prejudice that purpose of a patent which is to cover each new inventive concept therein no matter how it may later be disguised by variations in form or additions.

There has been chosen a specific embodiment of the drying apparatus and method for removing fluid from a traveling strand and showing a preferred arrangement of the apparatus and construction of the T-head. This specific embodiment has been chosen for the purposes of illustration and description as shown in the accompanying drawing wherein:

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 represents an an enlarged cross section of a T-head adapted for connection to a suction source, and

FIG. 2 represents a somewhat diagrammatic representation of a cooling or treating tank in cross section and showing an extruded product being fed to and through the fluid portion of the tank, thence over a wiper blade and then through a transverse passageway of the suction connected T-head shown in FIG. I.

In the following description and in the claims various details will be identified by specific names for convenience, these names, however, are intended to be generic in their application. Corresponding reference characters refer to like members throughout the two FIGS. of the drawing.

The drawing accompanying, and forming part of, this specification discloses certain details of construction for the purpose of explanation of the broader aspects of the invention, but it should be understood that these structural details may be modified in various respects and that the invention may be incorporated in other structural forms than shown.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIGS. 1 and 2, it is to be noted that an extrusion is shown as a tube l0 of plasti rubber or the like and which is fed to and through a body otfluid 12 in a tank 14. For extrusions of plastic or rubber the fluid is usually water which is circulated in tank 14 so as to provide a determined cooling or treating of the product as it is drawn through the tank. The depth of fluid, circulation, filtering and/or addition of fluid to the tank is conventional and is not restricted as to use in the described apparatus. As the tubing 10 reaches the far end of the tank 14, it is caused to be brought out of the fluid and over a wiper 16 which scrapes the gross accumulation of fluid from the underside and sides of the traveling product. The product 10, after it passes the scraper, is caused to enter and pass through a T-shaped drying head 20. The product, after passing through this head, as a dried tube is now identified as 22 and may be fed through measuring equipment not shown and then be wound upon a reel or otherwise accumulated for storage or use.

A determined amount of suction is provided to the head 20 by a conductor 24 which is attached to a suction inlet 26 of a wet-vacuum apparatus 28. This wet-vacuum apparatus is shown as seated on a collecting chamber 30 having a conical lower end 32 which is connected to a discharge pipe 34. This discharge pipe 34, as shown, has its lower end submerged in the fluid l2 ofthe tank I4. Under the influence of the negative ressure created by the wet-vacuum apparatus 28, fluid in the discharge pipe 34 is drawn upward to a level St: or height. This height 36 is, of course, determined by the amount of negative pressure produced by the wet-vacuum 28. The exhaust from this wet-vacuum is shown as being discharged from the vacuum-producing device through a discharge pipe 40.

Referring now in particular to FIG. 1 and the enlarged sectional view of the T-shaped drying head 20, it is to be noted that the traveling product is shown as a plastic tube of a determined size. This tube is fed to and through a determined inner diameter transverse passageway 44. This passageway is sized to provide a determined suction flow of air or gas between the outer surface of the tubing 10 and the inner wall of passageway 44, the direction of suction flow past the tubing being indicated by arrows. The inlet and outlet ends of the passageway through which the tube 10 travels is preferably flared as at 46. If desired the ends of the passageway may be straight; however, the suction flow of air or gas into and through the T-shaped drying head is usually with less turbulence and more efficiency when the ends of the passageway 44 are contoured as at 46.

The air or gas drawn in and around the traveling tubing 10 is fed to the wet-vacuum apparatus 28 through the upper connecting passageway 48 which is of a determined size and is adapted to be flow-connected to the vacuum hose 24. In practice, it has been found that a five-sixteenth of an inch diameter plastic tubing which is extruded at a conventional rate and is fed into a series of cooling baths of water and over the wiper 16 is very satisfactorily dried in a T-head whose passageway 44 is about 1-inch in diameter. The connecting passageway 48 and vacuum hose 24 may be about I k-inch in diameter. The wet-vacuum producing the suction for drying the 5/16 inch diameter tubing is a shop-type vacuum having a rating of two horsepower. The water drawn from the tubing and carried by conductor 24 to this wet-vacuum is collected in the receiving tank 30 and by gravity is fed into pipe 34. The fluid flowing down pipe 34 continues until it reaches the lever 36 of fluid drawn upwardly by the negative pressure in tank 30. This level is a more or less constant height because of the normal negative pressure in the tank 30. The constant supply of water being fed from tank 30 into discharge pipe 34 displaces the fluid in the pipe and causes the accumulated fluid constantly to discharge into the tank [4. When it is desired not to return this fluid to one ofthe cooling tanks, the fluid from tank 30 may be discharged into a sewer or other means. The end of the pipe 34 must be in a fluid receptible so that a column of fluid 36 is allowed to accumulate in the discharge pipe to permit a determined negative pressure to be developed in tank 30. The fluid from tank 30 is accumulated and discharged from the receiving receptible by gravity, by a pump or other conventional means.

The method and apparatus above-described is particularly satisfactory for drying plastic tubing and in particular a foamvinyl tubing. This same method and apparatus may also he applied to other extrusions of rubber, plastic and the like whether round or of irregular contour and cross section. This apparatus and method may be used in certain plating and painting operations where it is desired to provide an even rate of drying to the product being passed through the T-shaped drying head. These products, of course, include items such as wire being plated and many other 1 inch operations requiring a continuous drying operation provided by the passage of a determined velocity and amount of air or gas over the surface of the traveling product. This method and apparatus is particularly effective where the flow of air or gas must be particularly controlled. This control is provided by the very precise control of air flow as determined by regulation of the size of diameter 44 or modulation of flow in conductor 24. An extensive comparison test was conducted for the drying of foam-vinyl tubing as commercially produced. 'l'uhing, when dried by the conventional blasts of air, had an uneven drying of the surface resulting in staining of the tubing as well as unsatisfactory size control and storage. l'ubing dried by the method of this invention consistently produced a tubing having no stains on its outer surface and a substantially uniform outside and inside diameter cross-sectional configuration and the drying was uniform, consistent and complete.

It is, of course, realized that the length of the passageway portion 44 of the drying tube 20 will depend to a certain extent upon the speed of transport of the product and the desired amount and velocity of air or gas flow over the product being dried. From certain tests it is generally believed that a passageway length of approximately 4 to 6 inches for use with an extrusion of about five-sixteenth of an inch in diameter and traveling at a rate of up to 200 feet a minute produces a very satisfactory drying operation.

It is, of course, realized that placement of the wet-vacuum above the drying T-head 20 is merely a matter of preference, particularly when the fluid is being reclaimed and that other arrangements may be made whereby the outlet-connecting passageway may be directed sidewards or downwards just so long as the suction to both ends of the tube-receiving passageway is maintained and that the collected fluid is disposed of in a continuous manner.

it is to be noted that, as shown, the draining of the accumulated water or fluid from tank 30 is automatic and requires no additional equipment or controls. The wiping of the fluid from the traveling tube or wire and feeding the fluid as droplets to the collector requires an efficient T-head 20. An adjustable orifice on each end of passageway 44 reduces the effectiveness of the wipe as the efficiency depends upon the velocity and length of flow of air or gas over the traveling product. A smooth evenflow of air over the surface of the tube insures that the drying is complete, even and efficient. A regular diameter tube or wire and a regular diameter passageway insures that the flow of air or gas along the traveling product has the minimum or least turbulence. A passageway of larger diameter and having reduced diameter orifices at the ends of the passageway distorts the flow of air as well as the velocity.

Terms such as left," right," up, down, bottom," top, front," back," in," out, and the like are applicable to the embodiment shown and described in conjunction with the drawing. These terms are merely for the purpose of description and do not necessarily apply to the position in which the drying apparatus may be constructed or used.

The conception of the drying apparatus and its many applications is not limited to the specific embodiment shown but departures therefrom may be made and protection is sought to the broadest extent the prior art allows.

lclaim:

1. Apparatus for treating the outer surface of an advancing rodlike member which may be a continuously produced or treated rod, wire, tube and the like and in which the advancing outer surface of the member is to be wiped of fluid and the like by a flow of air, gas and the like over the surface of the member, the apparatus including:

2. a drying head disposed in way of the advancing member, the head having a through passageway arranged generally in the form of a T, the through passageway for the advancing member corresponding to the top cross bar of the T, the head having a connecting passageway to the conductingpassageway corresponding to the stem of the T, said through passageway having a determined cross section and sized to permit the free passage therethrough of the advancing rodlike member while providing a determined clearance for a suction flow of gas, air and the like past the outer surface of the advancing member, and with the connecting passageway being flow-connected to the conducting passageway at a point intermediate the ends of said through passageway;

b. a wet-type vacuum apparatus mounted on a fluid collecting chamber whose discharge outlet is connected to a discharge pipe having its lower end submerged in a fluid tank adapted to receive the fluid removed from the advancing member;

c. a conduit which is flow-connected from the connecting passageway of the T drying head and at its other end to the vacuum apparatus; and

e. means for discharging the fluid from the fluid collecting chamber to the discharge pipe.

2. Apparatus for treating the outer surface of a rodlike member as in claim 1 in which the connecting passageway is connected to the through passageway at substantially the midpoint of said through passageway.

3. Apparatus for treating the outer surface of a rodlike member as in claim 2 in which the cross-sectional area of the connecting passageway is about twice the size of the crosssectional area of the through passageway.

4. Apparatus for treating the outer surface of a rodlike member as in claim 1 in which the ends of the through passageway are flare contoured outwardly to provide a tapered inlet of greater diameter than the diameter of the through passageway this flare adapted to improve the airflow to and around the member being dried.

5. Apparatus for. treating the outer surface of a rodlike member as in claim 1 in which the vacuum apparatus is mounted above the treating tank, trough and the like and in which tank is contained one of the last supplies of fluid through which the advancing member is passed.

6. Apparatus for treating the outersurface of a'rodlike member as in claim 5 in which the discharge end of the discharge pipe is submerged in the fluid of one of the last advancing rodlike member treating tanks.

7. Apparatus for treating the outer surface of a rodlike member as in claim 6 in which there is provided a wiper disposed to scrape the gross supply of fluid from the outer surface of the advancing member, said wiper disposed in way of the advancing member at a point subsequent to the last treating tank having fluid through which the advancing member is passed.

8. APparatus for treating the outer surface of a rodlike member as in claim 1 in which the length of the through passageway is at least 4 inches in length.

9. The method of drying the outer surface of an advancing rodlike member which may be a continuously produced or treated rod, wire tube and the like and in which the outer surface of this member is wiped of fluid and the like by a flow of air, gas and the like over the outer surface of the advancing member, the method of drying including the steps of:

a. advancing the rodlike member at a determined rate and manner to and through a treating means of a fluid and the like which fluid is contained in a tank, trough and thelike;

the

of gas, air and the like past the outer surface of the advancing member; d. providing a source of reduced pressure by means of a vacuum apparatus for causing a suction flow of the gas,

air and the like to and through the drying head;

e. conducting this suction-actuated flow of gas, air and the like as well as the wiped fluid vapor from the advancing member through a connecting passageway in the drying head and through a conduit to the vacuum apparatus;

f. collecting the fluid vapor drawn to the vacuum apparatus in a fluid collecting chamber; and

g. discharging the fluid from said collecting chamber to a discharge pipe having its lower end submerged in a fluid tank adapted to receive the fluid wiped from the advancing member.

10. The method of drying the outer surface of an advancing rodlike member as in claim 9 in which there is provided the step of wiping the gross accumulation of fluid from the rodlike member immediately subse ue nt to said member leaving the treating tank, said wiping laemg provided by bringing the advancing rodlike member to and through a wiping scraper member.

ll. The method of drying the outer surface of an advancing rodlike member as in claim 9 in which the collecting of the drawn fluid vapor is into a hopper, and in which the discharge of fluid from this hopper is through a conduit whose distal end is submerged in a fluid supply.

12. The method of drying the outer surface of an advancing rodlike member as in claim 9 in which the source of reduced pressure is a wet-type vacuum apparatus mounted on a fluid collecting chamber mounted above the drying head. 

2. Apparatus for treating the outer surface of a rodlike member as in claim 1 in which the connecting passageway is connected to the through passageway at substantially the midpoint of said through passageway.
 2. a drying head disposed in way of the advancing member, the head having a through passageway arranged generally in the form of a T, the through passageway for the advancing member corresponding to the top cross bar of the T, the head having a connecting passageway to the conducting passageway corresponding to the stem of the T, said through passageway having a determined cross section and sized to permit the free passage therethrough of the advancing rodlike member while providing a determined clearance for a suction flow of gas, air and the like past the outer surface of the advancing member, and with the connecting passageway being flow-connected to the conducting passageway at a point intermediate the ends of said through passageway; b. a wet-type vacuum apparatus mounted on a fluid collecting chamber whose discharge outlet is connected to a discharge pipe having its lower end submerged in a fluid tank adapted to receive the fluid removed from the advancing member; c. a conduit which is flow-connected from the connecting passageway of the T drying head and at its other end to the vacuum apparatus; and e. means for discharging the fluid from the fluid collecting chamber to the discharge pipe.
 3. Apparatus for treating the outer surface of a rodlike member as in claim 2 in which the cross-sectional area of the connecting passageway is about twice the size of the cross-sectional area of the through passageway.
 4. Apparatus for treating the outer surface of a rodlike member as in claim 1 in which the ends of the through passageway are flare contoured outwardly to provide a tapered inlet of greater diameter than the diameter of the through passageway this flare adapted to improve the airflow to and around the member being dried.
 5. Apparatus for treating the outer surface of a rodlike member as in claim 1 in which the vacuum apparatus is mounted above the treating tank, trough and the like and in which tank is contained one of the last supplies of fluid through which the advancing member is passed.
 6. Apparatus for treating the outer surface of a rodlike member as in claim 5 in which the discharge end of the discharge pipe is submerged in the fluid of one of the last advancing rodlike member treating tanks.
 7. Apparatus for treating the outer surface of a rodlike member as in claim 6 in which there is provided a wiper disposed to scrape the gross supply of fluid from the outer surface of the advancing member, said wiper disposed in way of the advancing member at a point subsequent to the last treating tank having fluid through which the advancing member is passed.
 8. APparatus for treating the outer surface of a rodlike member as in claim 1 in which the length of the through passageway is at least 4 inches in length.
 9. The method of drying the outer surface of an advancing rodlike member which may be a continuously produced or treated rod, wire tube and the like and in which the outer surface of this member is wiped of fluid and the like by a flow of air, gas and the like over the outer surface of the advancing member, the method of drying including the steps of: a. advancing the rodlike member at a determined rate and manner to and through a treating means of a Fluid and the like which fluid is contained in a tank, trough and the like; b. removing this rodlike member from the tank of the treating fluid; c. moving the advancing rodlike member in way of and through a through passageway in a drying head, said through passageway being flow-connected to a vacuum source, the through passageway sized to permit the free passage therethrough of the advancing rodlike member while providing a determined clearance for a suction flow of gas, air and the like past the outer surface of the advancing member; d. providing a source of reduced pressure by means of a vacuum apparatus for causing a suction flow of the gas, air and the like to and through the drying head; e. conducting this suction-actuated flow of gas, air and the like as well as the wiped fluid vapor from the advancing member through a connecting passageway in the drying head and through a conduit to the vacuum apparatus; f. collecting the fluid vapor drawn to the vacuum apparatus in a fluid collecting chamber; and g. discharging the fluid from said collecting chamber to a discharge pipe having its lower end submerged in a fluid tank adapted to receive the fluid wiped from the advancing member.
 10. The method of drying the outer surface of an advancing rodlike member as in claim 9 in which there is provided the step of wiping the gross accumulation of fluid from the rodlike member immediately subsequent to said member leaving the treating tank, said wiping being provided by bringing the advancing rodlike member to and through a wiping scraper member.
 11. The method of drying the outer surface of an advancing rodlike member as in claim 9 in which the collecting of the drawn fluid vapor is into a hopper, and in which the discharge of fluid from this hopper is through a conduit whose distal end is submerged in a fluid supply.
 12. The method of drying the outer surface of an advancing rodlike member as in claim 9 in which the source of reduced pressure is a wet-type vacuum apparatus mounted on a fluid collecting chamber mounted above the drying head. 